Atactic polypropylene, a by-product in the production of crystalline polypropylene, has little value because of its poor physical properties and the inability to mold it in conventional thermoplastic molding operations. Attempts to upgrade actatic polypropylene by the addition of fillers have been largely unsuccessful because of incompatibility of the filler and the comparatively poor tensile strength, flex modulus, and impact properties of the filled material. The filled material is also of little use even for the least demanding applications.
The treatment of fillers with the organo-titanate chelates of the instant invention has been described in U.S. Pat. No. 4,087,402, issued May 2, 1978. While this patent recognizes that these chemicals make fillers more compatible with a variety of plastics, among them the alpha-olefins, there is no disclosure that such treatment would improve the properties of atactic polypropylene.